The process by which the mammalian immune system recognizes and reacts to foreign or alien materials is a complex one. An important facet of the system is the T cell response. This response requires that T cells recognize and interact with complexes of cell surface molecules, referred to as human leukocyte antigens ("HLA"), or major histocompatibility complexes ("MHCs"), and peptides. The peptides are derived from larger molecules which are processed by the cells which also present the HLA/MHC molecule. See in this regard Male et al., Advanced Immunology (J. P. Lipincott Company, 1987), especially chapters 6-10. The interaction of T cell and complexes of HLA/peptide is restricted, requiring a T cell specific for a particular combination of an HLA molecule and a peptide. If a specific T cell is not present, there is no T cell response even if its partner complex is present. Similarly, there is no response if the specific complex is absent, but the T cell is present. This mechanism is involved in the immune system's response to foreign materials, in autoimmune pathologies, and in responses to cellular abnormalities. Recently, much work has focused on the mechanisms by which proteins are processed into the HLA binding peptides. See, in this regard, Barinaga, Science 257:880 (1992); Fremont et al., Science 257:919 (1992); Matsumura et al., Science 257: 927 (1992); Latron et al., Science 257: 964 (1992).
The mechanism by which T cells recognize cellular abnormalities has also been implicated in cancer. For example, in PCT application PCT/US92/04354, filed May 22, 1992, published on Nov. 26, 1992, as WO92/20356 and incorporated by reference, a family of genes is disclosed which are processed into peptides which, in turn, are expressed on cell surfaces, and can lead to lysis of the tumor cells by specific CTLs. These genes are referred to as the "MAGE" family, and are said to code for "tumor rejection antigen precursors" or "TRAP" molecules, and the peptides derived therefrom are referred to as "tumor rejection antigens" or "TRAs". See Traversari et al., Immunogenetics 35:145 (1992); van der Bruggen et al., Science 254:1643 (1991), for further information on this family of genes.
In U.S. patent application Ser. No. 938,334, the disclosure of which is incorporated by reference, nonapeptides are taught which bind to the HLA-A1 molecule. The reference teaches that given the known specificity of particular peptides for particular HLA molecules, one should expect a particular peptide to bind one HLA molecule, but not others. This is important, because different individuals possess different HLA phenotypes. As a result, while identification of a particular peptide as being a partner for a specific HLA molecule has diagnostic and therapeutic ramifications, these are only relevant for individuals with that particular HLA phenotype. There is a need for further work in the area, because cellular abnormalities are not restricted to one particular HLA phenotype, and targeted therapy requires some knowledge of the phenotype of the abnormal cells at issue.
In a patent application filed on Dec. 22, 1992 in the name of Boon-Falleur et al., entitled "Method For Identifying Individuals Suffering From a Cellular Abnormality, Some of Whose Abnormal Cells Present Complexes of HLA-A2/Tyrosinase Derived Peptides and Methods for Treating said Individuals", the complex of the title was identified as being implicated in certain cellular abnormalities. The application does not suggest, however, that any other HLA molecules might be involved in cellular abnormalities.
The prior presentation of MAGE-1 by an HLA-A HLA-A1 molecule, as disclosed supra, also does not suggest that the protein can be presented by another HLA molecule. Thus, it is surprising that the very MAGE molecule presented by HLA-A1 has now been shown to be presented by HLA-C-clone 10. While the prior research is of value in understanding the phenomenon, it in no way prepares the skilled artisan for the disclosure which follows.